The present invention relates to film recorders for providing high quality computer generated graphic images on photographic film, and more particularly to a versatile film recorder having a user replaceable memory element containing color look up tables, exposure credit balances, diagnostic information, and/or data for providing new film recorder features or the like.
A film recorder is a photographic apparatus that uses photosensitive film. In a conventional film recorder, a light beam from a cathode ray tube ("CRT") or the like is controlled by a deflection system to scan across a stationary frame of photographic film to expose the film with an image. Typically, the images are generated by a computer for the production of slides, transparencies, photographs, or the like. Alternatively, the images can comprise natural images acquired by a scanner or television camera for subsequent processing by a computer.
Known film recorders, such as those sold under the trademark "SOLITAIRE" by Management Graphics, Inc. of Minneapolis, Minn., U.S.A , typically include a light source such as a CRT for producing a beam, a deflection system for scanning the beam across the face of the CRT, a system control and central processor unit ("CPU") for controlling the deflection system, and a camera (i.e., "film transport"). The latter component may include a film transport body, lens, lens mounting assembly, aperture plate, film plate, and film transport mechanism. On a Solitaire film recorder, an image to be recorded is first written on the phosphor of the CRT by deflecting an electron beam in a raster pattern and modulating the intensity of the beam. This process is analogous to the creation of a television picture. Alternatively, the image can be written on the CRT using well known time modulation techniques, wherein the beam intensity is constant but the time the beam is kept at each point is varied depending on the exposure required.
The resulting pattern (the "object image") on the CRT is optically imaged onto photographic film by the film transport, which contains the required optics and mechanism to advance the film to successive frames. Other types of light sources can be substituted for the CRT in a film recorder. Examples include fiber optic sources, lasers, and focused light impinging a rotating drum wherein one or more rotations are completed for each scan line.
In order for the film recorder to accommodate different film types (e.g., size in millimeters, sprocket hole type and arrangement, film processing type, such as E6, C41, etc.) and speeds (i.e., light sensitivity), specific information is needed about the particular film being exposed. In addition, color balance information is required for each particular film so that the images the film produces when developed will have the proper color renditions. Different films usually have different and distinctive color dyes and spectral sensitivity characteristics which must be correctly exposed by the light sources in the film recorder in order to result in a properly balanced picture. The methods for achieving the exposure control are highly varied and specific to the technology used in the film recorder.
If a film recorder permits different types of film to be used, the operator must supply information identifying which film is currently being exposed. This has usually been accomplished through a selection means such as a switch setting. Alternatively, the information may be contained in a data file loaded to the film recorder from a computer. If the settings made to the film recorder do not match the actual film loaded in the device, incorrect exposure may result.
A problem arises when new film types are marketed which have different characteristics than prior films. In particular, each new film will generally have different color balance requirements, which have not been programmed into existing film recorders. In order go update existing film recorders to operate with new film types, it has been necessary for internal changes to be made to the film recorder hardware, firmware, and/or software. This has typically required the dispatching of a field technical representative to each customer site, for modification of the film recorder to accommodate the new film type.
It would be advantageous to provide apparatus for easily upgrading film recorders to accommodate new film types. In particular, it would be advantageous to provide a means for enabling users to update the color look up tables in a film recorder to add new film types. It would be further advantageous if such apparatus provided additional features not heretofore available in a film recorder. Such features include, for example, the provision of credit balance information, allowing a user a certain number of exposures on a film recorder, at which time an additional credit balance can be purchased and programmed into the film recorder by the user in a simple manner. It would be still further advantageous for such apparatus to allow the film recorder to store diagnostic information in a replaceable memory element, which can be dispatched back to the factory for analysis and maintenance purposes. Other features not otherwise available in a film recorder would also be advantageously provided by such apparatus.
The present invention provides a user replaceable memory element having the foregoing advantages for use in a film recorder.